Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already cover the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=true), and the description adds real value beyond them: the change affects only displayed manual holdings, it is not a brokerage trade, and the target must be a manual record. It does not explain the concurrency/locking behavior implied by the expected_* parameters or how operation_id is used for retries, which would matter for a mutation tool.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three tight sentences with no waste: the action and scope come first, the user-facing effect second, and the precondition/constraint last. Every clause supplies information the agent needs.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The presence of an output schema and informative annotations means the description needn't cover return values or safety, and it handles the manual-vs-synced distinction well. However, for a six-parameter mutation tool with no schema descriptions, omitting any explanation of the expected_* concurrency parameters and operation_id leaves a meaningful gap in what an agent needs to invoke it correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0% across six parameters, so the description carries the burden, and it only clarifies transaction_id and implicitly quantity and price_per_share. The three most error-prone parameters — expected_quantity, expected_price_per_share (clearly optimistic-concurrency guards) and operation_id (an idempotency key) — are never mentioned, leaving the agent to guess at their purpose and at what happens on a mismatch.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names a specific verb (adjust), an exact resource (one manually recorded BUY transaction identified by ID), and scopes the fields touched (quantity and entry price). It also disambiguates this from a real brokerage trade and from synced/imported records, so an agent can tell it apart from record_my_portfolio_transaction and remove_my_portfolio_transaction.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives clear when-to-use context (correction of a manual BUY entry) and an explicit exclusion (synced and imported transactions cannot be changed), plus a procedural instruction to check the prior record and confirm the correction. What it lacks is routing to alternatives — for example, directing the agent to record_my_portfolio_transaction for a new entry or remove_my_portfolio_transaction to delete one.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.